Semiconductor device manufacturing method

Abstract

A semiconductor device manufacturing method includes forming a first film made of a first metal to an upper portion of a substrate, forming a second film made of an amorphous metal oxide or an microcrystalline metal oxide on the first film, subjecting the second film to a heat treatment, subjecting the second film after the heat treatment to a reduction treatment, forming a third film made of a ferroelectric material on the second film, and forming a fourth film made of a second metal on the third film.

1. A semiconductor device manufacturing method, comprising
 forming a first film made of a first metal to an upper portion of a substrate; 
 forming a second film made of an amorphous metal oxide or a microcrystalline metal oxide on the first film; 
 subjecting the second film to a heat treatment; 
 subjecting the second film to a reduction treatment after the heat treatment; 
 forming a third film made of a ferroelectric material on the second film; and 
 forming a fourth film made of a second metal on the third film. 
 
     
     
       2. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the heat treatment to the second film is performed in an atmospheric pressure. 
 
     
     
       3. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the heat treatment to the second film is rapid thermal annealing. 
 
     
     
       4. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the heat treatment to the second film is performed in an atmosphere containing oxygen. 
 
     
     
       5. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the second film has a thickness of between 10 nm and 40 nm. 
 
     
     
       6. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the second film is formed in a temperature of between 10° C. and 100° C. 
 
     
     
       7. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the second film is subjected to the reduction treatment by a solvent component included in raw material gas of the third film. 
 
     
     
       8. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the metal oxide is a result of oxidation of the first metal. 
 
     
     
       9. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the first metal is any of iridium, ruthenium, rhodium, and palladium. 
 
     
     
       10. The semiconductor device manufacturing method according to  claim 1 ,
 wherein an atmosphere for subjecting the second film to the heat treatment contains oxygen of 0.1% flow rate or more but 100% flow rate or less. 
 
     
     
       11. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the second film is subjected to the heat treatment from 600° C. or higher to 750° C. or lower. 
 
     
     
       12. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the second film is subjected to the heat treatment in a pressure equal to an atmospheric pressure or lower but equal to 1 Pa or higher. 
 
     
     
       13. The semiconductor device manufacturing method according to  claim 1 ,
 wherein after the first film is formed and before the second film is formed, the first film is subjected to the heat treatment in an inert atmosphere. 
 
     
     
       14. The semiconductor device manufacturing method according to  claim 13 ,
 wherein the first film is subjected to the heat treatment from 600° C. or higher to 750° C. or lower. 
 
     
     
       15. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the second film is subjected to the reduction treatment during a period for chemical vapor deposition of an initial layer of the third film. 
 
     
     
       16. The semiconductor device manufacturing method according to  claim 15 ,
 wherein the forming of the third film of the ferroelectric material includes a process of forming, on the initial layer by CVD (Chemical-Vapor Deposition), a core layer whose film-forming rate and film thickness are higher than those of the initial layer. 
 
     
     
       17. The semiconductor device manufacturing method according to  claim 15 ,
 wherein the initial layer is formed to have a film thickness of between 2.5 nm to 10 nm. 
 
     
     
       18. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the third film of the ferroelectric material is formed to have the same crystal orientation as that of the second film. 
 
     
     
       19. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the third film of the ferroelectric material is formed while a ratio of oxygen gas is being changed for induction into a film-forming atmosphere. 
 
     
     
       20. The semiconductor device manufacturing method according to  claim 1 ,
 wherein the third film is made of a ferroelectric material of a perovskite or bismuth-layer structure.